tune overview anchors + stack-title-bar placement

- SCENE_ANCHOR_OFFSET replaced with getSceneAnchorOffset() so the
  bifrost scene can compute its offset per-viewport instead of using
  a fixed px count. bifrost lands at offsetTop + 0.85 * vh so the arc
  and sub-headline are already drawn in; stack-scene drops from 2100
  to 1800 so the anchor lands mid-stack rather than on the 4th card's
  final beat.
- .stack-title-bar top drops from clamp(3.75rem, 7vh, 5.25rem) to
  clamp(1.25rem, 2.8vh, 1.85rem) so the title floats at the same
  vertical baseline as the fixed .site-mark wordmark in the top-left,
  instead of sitting below it.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

protected/bifrost.js

@@ -1232,24 +1232,30 @@
    *                          — see sceneOrder[] inside init().
    *                          Special value "hero" scrolls to top (0).
    */
-  // Per-scene scroll offsets in pixels. Added to the scene's offsetTop
+  // Per-scene scroll offsets. Added to the scene's offsetTop when a
-  // when a dot-nav button anchors to it, so the reader lands AFTER the
+  // dot-nav button anchors to it, so the reader lands AFTER the scene's
-  // scene's initial reveal rather than at an empty frame where the
+  // initial reveal rather than at an empty pre-scrub frame.
-  // scrub hasn't advanced yet.
   //
-  //   stack-scene — the pin is 5000px long; Phase A (cards falling in)
+  //   stack-scene — pin is 5000px long; Phase A (cards falling in) is
-  //     completes at ~0.42 of that (~2100px). Landing at +2100 puts
+  //     complete at ~0.42 of that (~2100px). 1800 lands just before the
-  //     the reader on the fully stacked state, just before the grid
+  //     4th card fully settles, so the reveal still has one tick to go.
-  //     rearrange begins in Phase B.
   //
-  //   hero, bifrost, bifrost-join — short reveal tweens; offsetTop is
+  //   bifrost — section is 200vh with a scrubbed reveal that runs from
-  //     already the correct landing spot so offset is 0.
+  //     top-top to bottom-bottom (100vh scroll range). The sub-headline
-  const SCENE_ANCHOR_OFFSET = {
+  //     fades in at ~0.83 of that. Offset is computed per viewport as
-    'hero':         0,
+  //     85% of vh so the reader arrives on the fully-drawn arc +
-    'stack-scene':  2100,
+  //     wordmark, regardless of display size.
-    'bifrost':      0,
+  //
-    'bifrost-join': 0,
+  //   hero, bifrost-join — short reveal tweens; offsetTop is already
-  };
+  //     the correct landing spot so offset is 0.
+  function getSceneAnchorOffset(sceneId) {
+    const vh = window.innerHeight;
+    switch (sceneId) {
+      case 'stack-scene':  return 1800;
+      case 'bifrost':      return Math.round(vh * 0.85);
+      default:             return 0;
+    }
+  }
 
   function scrollTo(sceneId) {
     if (!scrollerEl) return; // init() hasn't run yet — ignore
@@ -1260,7 +1266,7 @@
     // the scene element directly works in most cases but produces a tiny
     // non-zero offset (padding / border) — hard-code 0 for hero.
     const base = sceneId === 'hero' ? 0 : target.offsetTop;
-    const scrollY = base + (SCENE_ANCHOR_OFFSET[sceneId] || 0);
+    const scrollY = base + getSceneAnchorOffset(sceneId);
 
     if (lenisInstance && typeof lenisInstance.scrollTo === 'function') {
       // Lenis does the smooth animation. `immediate: false` uses the

protected/index.html

@@ -1076,13 +1076,13 @@ html {
      .sc-current token is updated from bifrost.js's ScrollTrigger onUpdate
      — 1/4 → 4/4 — one tick per landing card.
 
-     Vertical offset clears the fixed .site-mark (top:28px, width:118px)
+     Vertical top is aligned with the fixed .site-mark (top:28px) so
-     so the title sits below the wordmark instead of crashing into it.
+     the title rides beside the wordmark at the very top of the scene,
-     Horizontal padding on the left is bumped to push past the wordmark's
+     floating horizontally at the same baseline. Horizontal padding on
-     right edge; the right side uses the same edge token as the theatre. */
+     the left is sized to clear the wordmark's right edge (~146px). */
   .stack-title-bar {
     position: absolute;
-    top: clamp(3.75rem, 7vh, 5.25rem);
+    top: clamp(1.25rem, 2.8vh, 1.85rem);
     left: 0;
     right: 0;
     z-index: 20;
@@ -1090,7 +1090,7 @@ html {
     justify-content: space-between;
     align-items: baseline;
     gap: 1.5rem;
-    padding-left: clamp(10.5rem, 12vw, 12.5rem);
+    padding-left: clamp(10rem, 12vw, 12rem);
     padding-right: clamp(0.75rem, 2vw, 2.25rem);
     pointer-events: none;
   }